General Chat
Q:
I have been having problems with current drain on the alternator @ idle. I have posted this before. Now I have three alternators that I have tested and I believe I have the solution.
A little back ground on the matter. I have configured my car with an electric cooling fan, that requires about 12-16 Amps to run. The fuel pump say 7 amps to run under idle conditions. The ECU/Injectors that will draw about 4.5 Amps in the batch fire mode of operation. Then there is the electric water pump that draws about 7 Amps. That is about 35 Amps drain on the system with all of these components running.
The standard Alternator will give you about 25 Amps @ idle. The 150 Amp unit I got is a little better, just on the jagged edge of to much current draw.
So needless to say, there are conditions that will make the system discharge. So what this does is drop the battery voltage to about 11.6 volts worst case. When the battery voltage drops that far, guess what, the fuel management gets very screwed up and the car runs like crap. This has been a problem for me for some time, and really it took some time to realize what was happening. I was making adjustments to the program every time I started the car, or at least it seemed like it was that way.
So I did a good test, I supplied battery voltage to the rotor to see if I had a regulator problem, or if in fact the alternator could not supply enough current. Well it was the alternator and its ability to produce the required current that was the problem.
The rating of an alternator for maximum current really is not the way to go about selecting an alternator. You calculate the total current draw on the system to select the maximum current requirement. Then you calculate the current draw @ idle with the electronics on that operate to figure the minimum current requirements. If you have a setup similar to my setup, then you need a better unit to provide the required current @ idle.
I have bought one of the new Chevy Alternators, and according to the DB electric, this unit will provide 95 Amps @ idle. Now that should be enough to power the car @ idle in most cases.
I just hope, hope, this unit will do all that it was advertised to do. Then I can finally complete the tuning of this car!
Anyway, I thought it might be a good idea to start an Electrical page on my web page with a couple pictures of the different alternators. I can tell you one thing though, fabricating the mount and adjusting bracket for this unit was time consuming, and I used a CNC mill for the adjuster bracket. I think it turned out well.
signed pseudotechnician view point, Sniper S^$ker, with girly arms : UCC 1-207
A:
Jeff,
Again, thanks. I remember your first post. Could you please provide the part number of the alt. and where you got it from. I'm holding off until you complete your project. Looking forward to hearing the rest.
John
77280Z (Spooky), 83ZXT (Garage Queen), 86ZXT (Bulldog).
Proud owner of 10/03 Z car of the month.
A:
Damn good post. Thanks Jeff.......I quess that would of sucked big time on a really hot night sitting at a light with the stereo cranked up. By the way do you know what the idle out put of the Bosch ZX alternator at idle. You mentioned 25 amps but not sure what particular alternator that figure is for.
This whole world smells bad, I'd buy another if I had
back what I paid for another mother@#$%@# in a motorcade
A:
Hi John, I don't know the specifications of the stock alternator. I can make a call and get an answer I think. I will want that information for my web page thopugh.
The Hamilton Ferris alternator is vended out from a company in Texas. They make their own unit so it is new, all parts.
Anyway I will see about all of those parameters for all three units and list them on my page.
This last one is a really hot unit according to DB Electric. 05 Amps at idle and atotal of 200 amps potential. Internally regulated, single switched wire to turn it on. Making the brackest was somw work to get completed so I could mount the unit.
So we will see tomorrow if this was worth all my time and effort.
signed pseudotechnician view point, Sniper S^$ker, with girly arms : UCC 1-207
A:
"UCC 1-207"
Is that this?
"Performance or Acceptance Under Reservation of Rights."
"I reject your reality and substitute my own"
Please check out Thanks!
"You can get anything you want at Alice's Restaurant, excepting Alice"
A:
You can specify what terms are not acceptable, before you sign.
Remember how I am always asking people if they READ their contracts?
Simply lining through objectionable sections, signing and submitting it for acceptance is many times sufficient to get your teat out of a ringer later on.
Many people overlook your annotations, but in the same manner you can be held to the contract by your overlooking something in the fine print on a contract, they can be held liable for things you have lined out specifically to protect your rights.
From others below:
"When you are going to sign a contract ( drivers license, lease, buying a
automobile, snowmobile, a building permit, marriage license, devoice decree,
or any other document).
BEFORE you sign!!! you have the right to draw a fine line through any
thing that is not to your liking. It can be a number, a letter, a word or a
group of words. At this time you can add any thing you want in the contract.
Any changes you have made sign your name close to it and date it. A contract is to have all of the contract in full disclosure at the time of signing. If not the UCC 1-207 will stop you from giving up your rights on the contract you are about to sign and void out any part of the contract that you have not had the opportunity to view.
Now how the UCC 1-207 works.
After you put UCC 1-207 where your signature is going to be. " your
signature" is the last you thing you put on the document. When you pick up your pen from the signed contract it is consummated, you have given up your right to change the contract."
People Are Idiots, Just look around here and you will see!
Tony D: "Knowledgeable but Caustic"... rationull
My brother from another mother calls himself "Willie D"
A:
I'm happy with the 87 300ZX alternator I put in my 78 280Z. INSTANT FIT! I just had to crimp on different Pep Boy type female connectors for the back of the "NEW ALT." ... It also has TWO internal fans to keep it cool. I too am running a big electric fan and a three amp, six speaker stereo. So far, so good! My daily driver has had this set up for 16 months. Norm K
Norman Krell
A:
Thanks for the information Jeff & Norm, very timely for me.
Currently I have one 2 channel 4 ohm sub amp and 55/66W H4's Also been pondering a supplemental pusher fan for running the AC in stop & go traffic. Also need overhead for future Mega squirt etc
The low RPM soft spot….Like one almost needs a CVT (snowmobile clutch) pulley set up to increase the RPM of the alternator at low crankshaft RPM. And to limit it at high RPM.
BTW here are specs from a bench test ticket from an OEM replacement 82 ZX turbo Beck Arnley alternator.
Maximum output power 904 watts
Maximum output under full load 67 amps
Voltage regulator set point 14.7 (14.6 hot)
Turn on Speed (or indicator lamp out) 1552 RPM
Ripple voltage & maximum output 1.26 volts
Output current tested at 13.5 volts
RPM Amperage
1800 42
2000 48
3000 61
4000 65
5000 66
6000 67
-Pete
1978 Z ATK F54-P79
Drink Sobe No Fear Gold
Tokico Illuminas, Poly bushings,Techno Tuning TC rods. Bad Dog frame rails. Toyota 4 piston calipers & power slot rotors. MSA 2.5” turbo exhaust & K&N cold air intake. H4’s
A:
Ok Well I got the new alternator installed. I have to make some additional changes in the radiator hose fitting area. I made a spacer for the fitting and did an offset, or angled spacer to move the hose outlet up higher.
I have just enough room to slide the hos and clamp on the outlet. I think that is a little to close, the hose will burn up that way. So I have to take it apart again, and possibly modify my bracket a little.
The alternator does very well 13.8 volts when hot and it maintaines that with everything hot, and the lights on in the car.
I don't think it is doing the 95 Amps like advertised, but it is good enough to tune the car now I think LOL.
I am going to call today and see if I can turn up the output voltage slightly to get me to 14.2 volts if I can. I like the higher voltage for the cooling fan and the water pump, you would be surprised how much that .5 volts or so changes the fan cooling and the water pump cooling, mainly the cooling fan.
Anyway I will get this information up on my web page soon.
signed pseudotechnician view point, Sniper S^$ker, with girly arms : UCC 1-207
A:
electric water pump? where did you get that at? how much was it?
btw great post well detailed
-1988 300zxt Shiro SS edition, 120,000 miles
A:
You can buy the water pump at MSA, give them a call for pricing. The pump works well in the car.
signed pseudotechnician view point, Sniper S^$ker, with girly arms : UCC 1-207